Roller pump



Aug. 13, 1968 H. F. EVERETT ROLLER PUMP Filed July 13, 1966 I g EIlllllllllll Liz i.

FIG. 2.

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INVENTOR.

HAZEN F. EVERETT ATTORNEY United States Patent 3,396,669 ROLLER PUMPHazen F. Everett, 120 Bedford Road, Hillsdale, NJ. 07642 Filed July 13,1966, Ser. No. 564,988 9 Claims. (Cl. 103149) ABSTRACT OF THE DISCLOSUREA roller pump having a fluid conducting flexible tube arranged in ahelical turn against a cylindrical side wall surface of a housing cavityso as to have fluid pumped through the tube when squeezed against suchsurface .by a roller rolling along the turn is provided with a tubularshaft journalled coaxially with the side wall surface and having a rotorfixed thereto and carrying the roller, a drive shaft loosely received inthe tubular shaft, a handle pivoted on the rotor to move between aradially outward directed position where the handle is manually actuableto effect rotation of the rotor independent of the drive shaft and astored position extending over the tubular shaft, and a couplingrotatably connecting the drive shaft and tubular shaft only when thehandle is in its stored position. Desirably, such coupling isconstituted by a flat-sided element carried by the handle and which mayconstitute a knob thereon, and diametrical notches or recesses in thedrive shaft and tubular shaft alignable with each other to receive theflat-sided element in the stored position of the handle.

This invention relates generally to roller pumps, that is, to pumps ofthe type in which a flexible, preferably resilient tube for conducting afluid has a portion of its length disposed in the form of one or morehelical turns against a generally cylindrical surface, and a rollerpositioned to squeeze the tube against the cylindrical surface is madeto travel along a circular path which is concentric with the cylindricalsurface, thereby to propel the fluid through the flexible tube.

In roller pumps of the described character, the moving parts of the pumpdo not come in contact with the fluid conducted through the flexibletube so that such pumps are ideally suited for pumping fluids that areto be maintained in sterile condition or are corrosive. Roller pumpsfurther provide a gentle pumping action and this characteristic, and thepossibility of maintaining sterility, have led to the preference forroller pumps for the pumping of blood, for example, when the circulationof blood is bypassed around the heart and lungs of a patient duringopen-heart surgery.

Existing roller pumps are of complex construction, particularly when theflexible tube through which the fluid is conducted is to be replaceable,and replacement of the flexible tube is a time consuming operation andrequires substantial disassembly of the pump structure. Further, inexisting roller pumps, the roller is mounted on a rotor which issecurely connected to a drive shaft extending from a motor powered driveunit so as to be normally rotated by the latter. Although some of theexisting roller pumps are provided with a crank or handle by which therotor may be manually rotated when the drive unit is inoperative, suchmanual rotation must be effected with the rotor connected or coupled tothe drive shaft, and thus is opposed by the substantial resistance torotation of the reduction vgearing and motor of the drive unit. It willbe apparent that, when a roller pump is employed for the pumping ofbypassed blood during open-heart surgery, it is essential that thepumping of blood not be interrupted or adversely affected by a failureof the electric motor driving the pump. However, if manual rotation ofthe pump rotor is opposed by the resistance of the inoperative drive"ice unit, as in existing roller pumps, such manual rotation of therotor can cause extreme fatigue to the operator, particularly ifcontinued for an extended period.

Accordingly, it is an object of this invention to provide a roller pumpof simple construction which facilitates the replacement, in the pumphousing, of the flexible tube through which the fluid is to beconducted.

Another object is to provide a roller pump having a rotor carrying aroller along a circular path in response to rotation of the rotor, andwherein rotation of the rotor is normally effected by the couplingthereof to a drive shaft extending from an electric motor powered driveunit, but such coupling can be easily disengaged so as to permit manualrotation of the rotor independent of the drive shaft.

A further object is to provide a roller pump in which the extent towhich the flexible tube is squeezed or flattened against the cylindricalwall surface may be easily and accurately adjusted thereby to vary thevolume of fluid pumped through the flexible tube during each revolutionof the rotor.

A still further object is to provide a roller pump of the describedcharacter in which replacement of the fluid conducting tube, adjustmentof the squeeze or nip of the tube by the roller, and the change-overfrom powered to manual operation can be effected without the use of anyseparate tools or devices.

In accordance with an aspect of this invention, a roller pump isprovided with a housing having a cavity with a generally cylindricalside wall surface and inlet and outlet bores extending to and from thecavity in tangential relation to the side wall surface for leading afluid conducting flexible tube to and from at least one helical turnlying against the side wall surface, a tubular shaft is journalled inthe housing to extend into the cavity coaxially with the cylindricalwall surface of the latter and loosely receives a drive shaft extendingfrom a drive unit on which the pump housing is mounted, a rotor is fixedon the tubular shaft for rotation therewith within the cavity andcarries roller means for squeezing the flexible tube against the sidewall surface and rolling along the helical turn of the tube uponrotation of the rotor, a handle is pivoted on the rotor to move betweena radially outward directed position, where the handle is manuallyactuable to eifect rotation of the rotor independent of the drive shaft,and a stored position extending over the tubular shaft, and means on thehandle is operative to rotatably couple the tubular shaft with the driveshaft when the handle is in its stored position.

In accordance with another aspect of this invention, the inlet andoutlet bores for leading the flexible tube to and from the cavity of thehousing have their axes extending in opposed directions in the sameplane, and the housing is divided, at such plane containing the axes ofthe bores, into two separable portions, with mounting means beingprovided to normally hold one of the housing portions against the otherof such portions at the plane of division therebetween, and suchmounting means is actuable to permit separation of the two housingportions at the plane of division therebetween, thereby to facilitatethe replacement of the flexible tube in the housing cavity and in thebores leading to and from such cavity.

In accordance with another feature of this invention, the roller forsqueezing the flexible tube against the cylindrical side wall surface ofthe housing cavity is rotatably mounted on a member which is pivotallycarried by the rotor, with the pivoting axis of such member beingparallel to, and spaced from the axes of rotation of the rotor and ofthe roller so that pivoting of the member relative to the rotor effectsmovement of the roller toward and away from the side wall surface, andadjustable means member with respect to'the rotor and thereby determinethe extent of the squeezing of the flexible tube by the roller.

The above, and other objects, features and advantages of this invention,will be apparent in the following detailed description of anillustrative embodiment thereof which is to be read in connection withthe accompanying drawing, wherein:

FIG. 1 is a side elevational view of a roller pump embodying thisinvention;

FIG. 2 is a top plan view of the pump of FIG. 1, but with a lid thereofshown in open position and partly broken away;

FIG. 3 is a vertical sectional view taken along the line 33 on FIG. 2;

FIG. 4 is a detail sectional view taken along the line 44 on FIG. 3, butwith a handle of the pump being shown in its position for effectingmanual operation of the pump;

FIG. 5 is a detail sectional view taken along the line 5-5 on FIG. 2,but with a portion of the pump housing being shown in its open positionto facilitate replacement of the flexible tube through which fluid is tobe conducted;

FIG. 6 is a detail side elevational view of a rotor assembly included inthe pump;

FIG. 7 is a fragmentary sectional view taken along the line 77 on FIG.4;

FIG. 8 is a fragmentary sectional view taken along the line 88 on FIG.4; and

FIG. 9 is a fragmentary elevational view of a portion of the rotorassembly, as viewed from the side opposed to that appearing on FIG. 6.

Referring to the drawing in detail, and initially to FIGS. 1 and 2thereof, it will be seen that a roller pump 10 embodying this inventiongenerally comprises a pump housing 11 having an upwardly opening cavity12 with a cylindrical side wall surface 13, and further having bores 14and 15 that extend from the opposite sides of housing 11 and open intocavity 12 in tangential relation to side wall surface 13. As shown,bores 14 and 15 are disposed at different levels above the bottom ofcavity 12 (FIG. 1) and have their axes lying in the same plane 16 atwhich, in accordance with this invention, housing 11 is divided intoportions 11a and 11b, respectively. It will be seen that the plane 16 ofseparation or division between housing portions lla and 11b extendschordally across cavity 12 close to side wall surface 13 thereof so thatthe major part of cavity 12 is disposed in housing portion 11a (FIG. 2).

Housing portion 11a is formed with a flange 17 (FIGS. 1, 3 and 5)projecting horizontally from the bottom of portion 11a beyond the face16a thereof which corresponds to the plane of separation, and the endsof flange 17 are formed with cut-outs 18 (FIGS. 1 and 5) to receive lugs19 depending from housing portion 11b. Lugs 19 are pivotally mounted onthe ends of a shaft 20 extending longitudinally through flange 17 andprojecting into cutouts 18. Thus, housing portion 11b is pivotallymounted for movement about the axis of shaft 20 be tween an openposition (FIG. 5) in which faces 16a and 16b of the housing portions aresubstantially angularly separated, and a closed position (FIG. 1) inwhich faces 16a and 16b of the housing portions come together at theplane of separation 16.

Housing portion 11b may be urged to its open position (FIG. 5) by meansof one or more helical compression springs 21 seated in sockets openingat faces 16a and 16b above the axis of shaft 20. In order to normallyhold housing portion 11b in its closed position, housing portion 11b maybe formed, adjacent its opposite ends, with extensions 22 havingthreaded bores extending therethrough to receive locking screws 23.Screws 23 exit from-.- the respective threaded bores at the lower endsof extensions 22 and are engageable with flange 17. Thus, when lockingscrews 23 are turned in the direction to effect upward'rnovement thereofwith respect'to housing portion 11b, the latter is free to be rocked bysprings 21 to its open position (FIG. 5). However, when locking screws23 are turned in the opposite direction to project increasingly downwardfrom extensions 22, the lower ends of screws 23 bear on flange 17 inback of shaft 20, and thus effect rocking of housing portion 11b to itsclosed position(FIG.1).

It will be apparent that, when housing portion 11b is in its openposition, there is an open gap in side wall surface 13 of the majorpart-of cavity 12 defined in housing portion 11a and, further, the bores14 and 15 appear as semi-cylindrical grooves in the angularly separatedfaces 16a and 16b of the housing portions. Thus, a flexible, preferablyresilient tube 24 of plastic or the like can be easily laid in the opengroove-like sections of bores 14 and 15 in face 16a and formedtherebetween into a helical turn lying against side wall surface 13 ofthe major part of cavity 12 in housing portion 11a. After suchdisposition of flexible tube 24 with respect to housing portion 11a,housing portion 111) may be moved to its closed position, as describedabove, so as to enclose, and thereby hold, portions of tube 24 in bores14 and 15.

Housing portion 11a further has a vertical bore 25 concentric withcavity 12 and extending from the bottom of the cavity to open at thelower surface of the housing (FIG. 3). Bore 25 has a flange 26 thereinintermediate its length to provide seats for tapered roller bearings 27aand 27 b disposed below and above flange 26 within bore 25. Bearings 27aand 27b rotatably support a tubular shaft 28 having an outwardlydirected flange 29 at its upper end (FIGS. 2 and 4) and an externallythreaded lower end portion 30.

A rotor assembly 31 is carried .by the upper end portion of tubularshaft 28 which extends into cavity 12. Rotor assembly 31 includes anelongated body 32 which, approximately at its middle, is formed with avertic'albotre 33 (FIGS. 3 and 7) diametrically dimensioned to permittubular shaft 28 to extend downwardly therethrouglh with flange 29 ofthe tubular shaft seating on the upper surface of rotor body 32. Rotorbody 32 is held against rotation relative to tubular shaft 28, forexample, by a set screw 34 (FIG. 6). Disposed between rotor body 32 andupper bearing 27b is 'a cover or spacing disk 35, and nuts 36 areengaged with the threaded lower portion of shaft 28 to hold the latteragainst upward removal from within bearings 27:: and 27 b and further toretain the bearings in seated engagement with flange 26.

As indicated on FIGS. 1 and 3, pump housing 11 is intended to be mountedupon a drive unit 37 that contains an electric motor and reductiongearing (not shown) through which the motor effects rotation, at acontrolled variable speed, of an upwardly projecting drive shaft 38.

Drive shaft 38 is dimensioned to extend loosely into tubular shaft 28and to project to the upper end of the latter when housing 11 is mountedon top of drive unit 37. As shown on FIG. 1, housing 11 may be removablysecured on drive unit 37 by means of bolts 39 (FIG. 1) having theirheads received in cavities 40 provided in the opposite sides of thecasing of drive unit 37 and extending through holes opening upwardlyfrom cavities 40 into tapped bores 41 opening at the bottom surface ofhousing portion 11a.

Rotor assembly 31 further includes a handle 42 which is pivotallymounted, at one end, on a pivot 43 extending laterally between lugs 44projecting upwardly from rotor body '32 adjacent one end of the latter.Thus, handle 42 is :swingable between a stored position where it extendslongitudinally on top of body 32 over the upper end of tubular shaft 28,as indicated in full lines on FIGS. 2 and 3, and a radially outwarddirected position, as indicated in broken lines on FIG. 3 and in fulllines on FIG. 4. The upper end of tubular shaft 28 has diametricallyopposed notches 45 opening through flange 29 (FIGS. 4

and 7) and drive shaft 38 has a diametrically extending slot 46 thereinfor angular registration with notches 45. A

flat-sided element 47 is mounted on handle 42 adjacent the free end ofthe latter, as by a pin 48 (FIG. 4), so as to be capable of rotationrelative to handle 42 about an axis at right angles to the axis of pivotpin 43. Element 47 is dimensioned and located with respect to handle 42so that, when the latter is in its stored position extending over theupper end of tubular shaft 28, flat-sided element 47 depends from handle42 and engages simultaneously in notches 45 of tubular shaft 28 and inslot 46 of drive shaft 38, thereby to couple rotor assembly 31 to driveshaft 38 for rotation by drive unit 37.

However, when handle 42 is pivoted to its radially outward directedposition, element 47 projects upwardly from the outer end of the handleand constitutes a knob that can be conveniently grasped for elfectingmanual rotation of rotor assembly 31. Further, when handle 42 is in itsradially outward directed position, rotor assembly 31 is uncoupled fromdrive shaft 38, and thus its manual rotation can be effected withoutbeing opposed by the resistance to rotation of drive unit 37 when thelatter is inoperative. In order to yieldably retain handle 42 in eitherits stored position or its radially outward directed position, handle 42has one side thereof formed with recesses or depressions 49 (FIG. 3) atdiametrically opposed locations with respect to its pivoting axis, andsuch recesses are selectively engaged by a spring urged ball or detent50 (FIG. 4) mounted in one of the lugs 44.

The end of rotor body 32 remote from lugs 44 has an extension 51 (FIG.4), at one side, carrying a pivot pin 52 which is vertical, that is,parallel to the axis of rotation of the rotor assembly. A roller supportmember 54 (FIG. 6) has upper and lower webs 55 spaced apart to engageabove and below extension 51 and being connected, at one side, by a baror post 56. Webs 55 are pivotally mounted on the ends of pin 52projecting from extension 51 so that roller support member 54 is mountedfor pivoting with respect to rotor body 32. A roller 57 is rotatablymounted on a shaft 58 carried, at its opposite ends, by webs 55 andbeing parallel, and offset with respect to pivot pin 52. Thus, pivotingof member 54 relative to rotor body 32 is effective to move roller 57toward and away from side Wall surface 13 of cavity 12, and thereby varythe extent to which roller 57 squeezes the helical turn of flexible tube24 lying against surface 13.

A hollow screw 59 extends laterally through a tapped bore in extension51 of the rotor body (FIGS. 4 and 8) and is provided wtih a manuallyactuable head or knob 60 at its outer end. The interior of hollow screw59 is threaded, as at 61 (FIG. 8), and receives a setting screw 62 whichprojects a variable distance from the inner end of hollow screw 59 toengage against the bar or post 56 of roller support member 54. A lockscrew 63 may also be threaded into screw 59 to hold the adjustment ofsetting screw 62 with respect to hollow screw 59. It will be apparentthat rotation of knob 60 causes variation of the axial position of screw59, and of the end of setting screw 62 projecting therefrom, relative toextension 51 and thereby varies the extent to which member 54 can pivotin the direction for moving roller 57 away from side wall surface 13.

As shown on FIG. 9, the outer surface of knob 60 and the adjacentsurface of rotor body 32 may be provided with a cooperating scale 64 andindex 65 calibrated to indicate the position of roller 57 with respectto side wall surface 13 or the extent to which roller 57 squeezes thehelical turn of tube 24.

The described arrangement for setting the position of roller supportmember 54 with respect to rotor body 32 makes it possible to apply scale64 and index 65 to the respective surfaces prior to assembly of thepump, without regard to the manufacturing tolerances, and, afterassembly of the pump, to adjust setting screw 62 with respect to hollowscrew 59 so that roller support member 54 is held in the position whereroller 57 engages side wall surface 13 when knob 60 is rotatonallypositioned to dispose the zero indication on scale 64 next to, index 65.Thereafter, setting screw 62 is locked relative to hollow screw 59 bylocking screw 63 so that subsequent indications provided by scale 64 andindex 65 will accurately reflect the position of roller 57 with respectto the adjacent side wall surface 13.

In order to ensure that tube 24 is held at vertical positions on sidewall surface 13 within the axial extent of roller 57, and thus is notsqueezed out beyond the ends of the roller and pinched between thelatter and webs 55, the edges of webs 55 of roller support member 54closest to side wall surface 13 are provided with lips 66 (FIGS. 6 and9) directed toward each other beyond the ends of roller 57.

Pump 10 may further be provided with a cover or lid 67 (FIGS. 1 and 2)in the form of a plate 68, preferably of a transparent plastic, which iscoextensive with the top of housing 11, and which has secured thereto,adjacent one edge of the plate 68, lugs 69 that are laterally bored toreceive an axle 70 extending laterally between extensions 22 of housingportion 111). Thus, lid 67 is swingable about axle 70 between a closedposition, as shown in full lines on FIG. 1, Where plate 6-8 extends overthe top of housing 11 and is spaced upwardly from rotor assembly 31 bythe engagement of lugs 69 with the top surface of housing 11, and anopen position, as indicated in broken lines on FIG. 1 and in full lineson FIG. 2, where the lid or cover 67 is disposed to one side of the pumphousing to permit free access to rotor assembly 31, for example, when itis desired to effect manual rotation thereof, adjustment of the settingof roller 57 or replacement of tube 24.

It will be apparent that, in roller pump 10, as described above,replacement or installation of tube 24 in the pump housing merelyrequires the movement of housing portion 11b to its open position bymanipulation of screws 23 and, during such removal or installation oftube 24, rotor body 32 is preferably disposed so that the end portionthereof carrying roller support member 54 extends toward the gap incylindrical side surface 13 defined at face 16a of housing portion 11a.By reason of the ease with which tube 24 can be replaced, such tube canconveniently be part of a disposable assembly of previously sterilizedtubing suitably connected to associated apparatus, for example, anoxygenator or the like. Further, it will be apparent that the changeoverfrom operation of the pump by motor powered drive unit 37 to manualoperation can be quickly effected merely by moving handle 42 from itsstored position where element 47 serves to couple together shafts 2-8and 38, to its radially outward directed position where element 47constitutes a knob that can be conveniently grasped for manuallyrotating rotor assembly 31. It is also obvious that adjustments of theposition of roller 57 with respect to side wall surface 13 can beconveniently and accurately effected merely by rotation of knob 69,thereby to adjust the volumetric rate and pressure at which fluid ispumped through tube 24. It should be noted that, in replacing tube 14,changing over from powered to manual operation or adjusting the squeezeor nip of tube 14, no tools or devices separate from the pump 10 arerequired. The foregoing features of pump 10 are all particularlyadvantageous for its application in the pumping of blood or other fluidsin surgical apparatus, but it will be apparent that such features areadvantageous when the pump is employed in other a plications, forexample, in the chemical industry for pumping corrosive fluids that donot attack the plastic material of tube 24.

Although an illustrative embodiment of the invention has been describedin detail herein with reference to the accompanying drawing, it is to beunderstood that the invention is not limited to that precise embodiment,and that various changes and modifications may be effected therein byone skilled in the art without departing from the scope or spirit of theinvention, as defined in the appended claims.

What is claimed is:

1. A roller pump comprising a housing having a cavity with a generallycylindrical side wall surface and inlet and outlet bores extending toand from said cavity in tangential relation to said side wall surfacefor leading a fluid conducting flexible tube to and from at least onehelical turn lying against said surface, a tubular shaft journalled insaid housing coaxially with said cylindrical wall surface and having anend portion projecting into said cavity, a drive shaft loosely receivedin said tubular shaft and extending into said end portion thereof, arotor fixed on said end portion of the tubular shaft for rotationtherewith, roller means carried by said rotor for squeezing the flexibletube against said side wall surface and rolling along the turn of thetube upon rotation of said rotor, a handle pivoted on said rotor to movebetween a radially outward directed position, where the handle ismanually actuable to effect rotation of said rotor independent of saiddrive shaft, and a stored position extending over said tubular shaft,and means operative to rotatably couple said tubular shaft with saiddrive shaft only when said handle is in said stored position thereof.

2. A roller pump according to claim 1; wherein said end portion of thetubular shaft has diametrically opposed notches opening axially thereinand said drive shaft has a diametrical slot opening axially and beingalignable with said notches, and said means for rotatably coupling thetubular shaft with the drive shaft includes a fiat-sided element carriedby said handle and fitting into the aligned slot and notches in saidstored position of said handle.

3. A roller pump according to claim 2; wherein said flat-sided elementis mounted on said handle for rotation relative to the latter about anaxis which is parallel to, and spaced from the axis of rotation of saidtubular shaft and rotor in said radially outward directed position ofthe handle to constitute a knob which can be grasped in effecting themanual rotation of the rotor.

4. A roller pump according to claim 1; further comprising detent meansfor releasably retaining said handle in each of said radially outwarddirected and stored positions thereof.

'5. A roller pump according to claim 1; wherein said inlet and outletbores have their axes extending in oppose-d directions in the same planeand said housing is divided, at said plane, into two portions; andfurther comprising means mounting one of said portions of the housing onthe other of said portions and permitting separation of said one portionfrom said other portion at said plane, thereby to facilitate theinstallation of the flexible tube in said bores and cavity.

6. A roller pump according to claim 5; wherein said means mounting saidone portion on said other portion includes pivot means defining an axisabout which said one portion is rockable between closed and openedpositions with respect to said other portion, said axis of the pivotmeans being parallel to, and spaced from said axes of the bores.

7. A roller pump according to claim 6; further comprising meansyieldably urging said one portion of the housing to rock said openposition, and manually operable means for releasably retaining said oneportion in said closed position thereof.

8. A roller pump according to claim 1; wherein said rotor includes abody extending radially from said tubular shaft, a member mounted onsaid body adjacent said side wall surface and being pivotally movablewith respect to said body about an axis parallel to the axis of saidtubular shaft, said roller means including a roller mounted on saidmember for rotation about an axis parallel to, and offset from said axisof pivoting of said member so that said roller moves toward and awayfrom said side wall surface in response to pivoting of 'said member withrespect to said body, and adjustable means to pivotally position saidmember with respect to said body and thereby determine the extent of thesqueezing of the flexible tube by said roller means.

9. A roller pump according to claim 8; wherein said adjustable meansincludes a hollow screw extending threadably through said body in adirection at right angles to and spaced from said axis of pivoting ofsaid member on said body, a setting screw threaded in said hollow screwand projecting axially from one end of the latter to bear against asurface of said member for limiting pivotal movement of the latter inthe direction moving said roller away from said side wall surface, ahead on the other end of said hollow screw by which the latter can bemanually adjusted, and cooperating scale and index means on said headand an adjacent surface of said body calibrated to indicate the positionof said roller with respect to said side wall surface.

References Cited UNITED STATES PATENTS 2,035,159 3/1936 Henry 103-1492,306,751 12/1942 Reymond 103-149 2,909,125 10/1959 Daniels 103-1492,955,543 10/1960 Daniels 103-149 FRED C. MATTERN, JR., PrimaryExaminer.

WILBUR J. GOODLIN, Assistant Examiner.

